Why? When? Who? What?!!

I don't understand. Girl Terror seems to be bright enough. She passed all the important milestones on time. But still, there are moments in every day when I wonder if some of her wires don't connect.
Why can't she scoot off the toilet and get the roll of toilet paper when it's just out of reach? She is more than able and willing to leap up and waddle to the door, panties around her ankles, so she can shove her brother out of the bathroom. She needs her "private-sy", you know. Speaking of which, why does she need so much privacy from her brother, but can't understand why he might want some privacy of his own? Bum changing time is not the best time to ask him questions, show him things, or just generally hang around. She doesn't get it, though.
Why must we discuss the same questions each and every day? On any given day, I answer at least half of these queries:
1. "When I wash my hands, should I use some soap?"
2. "Why do I hafta pee before bed? My body says it doesn't have to go right now."
3. "Should I put these panties in the laundry basket?" (Each and every morning.)
4. "What's your favourite colour, Mummy? Know what mine is?"
5. "Can I finger paint?"
6. "Why can't I finger paint?"
7. "How much of my supper should I eat?"
8. "How long should I sleep?"
9. "What would happen if a person was on top of a volcano?"
10. "Can I flush?"

Does she forget the answers? Is it so hard to remember this stuff? I realize she might be making sure that I know the answers, but I don't know how to assure her that I do. I really, really do. I know when to flush, use soap, my favourite colour. I know ALL the answers. Maybe that's why she keeps asking me this stuff. She's checking for Alzheimers.